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703-205-0600
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Planning a Microwave radio receiver Link
By Michael F. Young
President and CTO
YDI Wireless
Background
Most installers know that clear bank bill of sight is required between two barbels, but thither is a lot more to it than
that. In this article, the basics of calculative and planning a microwave radio link leave be discussed.
Some manufacturers of OFDM (Orthogonal Frequency Division Multiplexing)-based equipment claim to offer
doctor wireless systems with non-line-of-sight functionality. However, this article does not discuss the RF
propagation issues associated with non-line-of-sight gear.
bill of Terms
Before getting to the nuts and bolts of designing a link, somewhat fundamental terms and concepts need to be
reviewed.
Free Space Loss
As signals broadcast out from a radiating source, the vitality is spread out over a larger surface area. As this
occurs, the strength of that signal gets weaker. Free space loss (FSL), mensural in dB, specifies how much the
signal has weakened over a given distance.
bit 1 shows the formula to calculate FSL and what the notional loss would be at sample distances. The
type of antenna used has no effect on FSL, since at both appreciable distance all antennas look like a pointsource radiator.
Note that the difference in FSL between a 2.4 gigahertz link and a 5.8 GHz link is always to the highest degree 8 dB,
regardless of the distance. This is one of the reasons why 802.11a wireless topical anaesthetic area network (WLAN) devices
will have less than half the range of a 2.4 GHz WLAN device (e.g., 802.11b).
Figure 1 Free Space Loss (FSL)
Fresnel Zone
Radio waves rifle in a straight line, unless something refracts or reflects them. But the energy of radio waves is
not pencil thin. They spread out the far they get from the radiating source รข€" like ripples from a list thrown
into a pond.
The area that the signal spreads out into is called the Fresnel zone (pronounced fra-nell)....If you destiny to get a full essay, order it on our website: Orderessay
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